I created something called Group Games with Pirate vs Undead with up to 48 players on 1 big cinema screen. See video below. The website is not in effect any more but the playing is relevant.
Now Roku could support and create these types of games. They would be perfect for home and out of home like cinema experiences. Players will quickly adopt phone controller once they see how good it is. I created after being CEO of Palace Cinemas in Central Europe. It's a way to allow all players to have a great experience rather than the one stream projected on big screen. There's all kinds of opportunities. Once shown to work, there are many big games that could have this type of arena format.